Too much hp-talk, let's talk real life numbers!
10-18-2005, 04:09 PM
#107
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Originally Posted by Tomas L
Ok, this is as I understand it the given configuration.
2,5L engine
boost 1.72 bar
6000 rpm
533 rwhp
If we assume 11% driveline loss then we get 600 hp at the flywheel.
We can also assume an AFR at around 12.2:1
Then we have the following parameters to play with:
BSFC, Normally between 0.5 for a well tuned high compression 16v engine at high 12 AFR, and 0.6 for a less optimised low compression engine. A turbo engine should be between 0.55 and 0.6 due to the low compression ratio and the fact that we have to run a little richer AFR.
VE, Maybe 75% for a standard engine and a little over 100% for a well tuned racing engine.
Temperature after the intercooler. 20° indicating a 100% effective IC.
To reach 600 hp at the above stated circumstances we need a BSFC of 0.5 lb/(hp*h), a VE at 112% and a temperature of 20°C after the intercooler.
In other words, to achive this power level you need the efficiency of a highly tuned high compression naturally aspirated engine, better volumetric efficiency than a racing engine and a 100% effective IC.
I may have done some calculation errors or messed things up otherwise. It's up to each individual to draw his own conclusions from this.
Tomas
2,5L engine
boost 1.72 bar
6000 rpm
533 rwhp
If we assume 11% driveline loss then we get 600 hp at the flywheel.
We can also assume an AFR at around 12.2:1
Then we have the following parameters to play with:
BSFC, Normally between 0.5 for a well tuned high compression 16v engine at high 12 AFR, and 0.6 for a less optimised low compression engine. A turbo engine should be between 0.55 and 0.6 due to the low compression ratio and the fact that we have to run a little richer AFR.
VE, Maybe 75% for a standard engine and a little over 100% for a well tuned racing engine.
Temperature after the intercooler. 20° indicating a 100% effective IC.
To reach 600 hp at the above stated circumstances we need a BSFC of 0.5 lb/(hp*h), a VE at 112% and a temperature of 20°C after the intercooler.
In other words, to achive this power level you need the efficiency of a highly tuned high compression naturally aspirated engine, better volumetric efficiency than a racing engine and a 100% effective IC.
I may have done some calculation errors or messed things up otherwise. It's up to each individual to draw his own conclusions from this.
Tomas
How about his cylinder head? Bigger valves, etc. Dont know about raised compression....
10-18-2005, 04:19 PM
#108
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Originally Posted by theedge
How about his cylinder head? Bigger valves, etc. Dont know about raised compression....
Since the peak power rpm was given in the dyno chart, we can only play with VE.
10-18-2005, 04:38 PM
#109
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Originally Posted by Black Arrow
I did some runs the other day, and the rear tires started slipping in 4th at 150kpr! Pretty scaring. (cold outside!!)
10-18-2005, 04:40 PM
#110
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Originally Posted by Tomas L
A better flowing head is accounted for in the VE factor and the rpm where peak power is produced.
Since the peak power rpm was given in the dyno chart, we can only play with VE.
Since the peak power rpm was given in the dyno chart, we can only play with VE.
10-19-2005, 12:11 AM
#111
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Corleone,
That's an incredibly fast ride you got there.
How much displacement and/or compression?
Get ready for ST's run;
although he will probably be the only one using race gas even though there was no mention of using race gas within the last 100+ posts.
That's an incredibly fast ride you got there.
How much displacement and/or compression?
Get ready for ST's run;
although he will probably be the only one using race gas even though there was no mention of using race gas within the last 100+ posts.
10-19-2005, 12:14 AM
#112
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Originally Posted by TurboTommy
Corleone,
That's an incredibly fast ride you got there.
How much displacement and/or compression?
Get ready for ST's run;
although he will probably be the only one using race gas even though there was no mention of using race gas within the last 100+ posts.
That's an incredibly fast ride you got there.
How much displacement and/or compression?
Get ready for ST's run;
although he will probably be the only one using race gas even though there was no mention of using race gas within the last 100+ posts.
Forget about the race fuel; with the S2 box his times are going to be quick!
10-19-2005, 01:56 AM
#113
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"ST has the capability to take advantage of race fuel".
If it would read:
"ST has the tuning capability to take advantage of high boost on pump gas." Then we might actually have something, here.
There are actually a few of us, here, with big enough turbos, and adequate fuel management where we could effeciently turn up the boost without detonation with race gas. Then obviously the acceleration would be that much faster.
We are comparing fast street cars, are we not? Comparing ourselves to other 951s, ferraris, vettes, 996tts, or whatever. A street car you use everyday, possble child seat (STs), get groceries, pick up chicks, or whatever. Reliable fun. The same fun and convenience you have with other cars; the same power is available at ALL times.
You could be taking a weekend getaway with your cool wife/girlfriend, but the rare chance to go headsup with the CarreraGT that just popped up in your rearview has eluded you because you're all out of race gas. This is real life; not the dyno world.
Again, I'm assuming we're comparing street cars. It's not really that user friendly of a street car if your whole life evolves around where your race gas supply is.
The S2 box will do nothing for his times.
If it would read:
"ST has the tuning capability to take advantage of high boost on pump gas." Then we might actually have something, here.
There are actually a few of us, here, with big enough turbos, and adequate fuel management where we could effeciently turn up the boost without detonation with race gas. Then obviously the acceleration would be that much faster.
We are comparing fast street cars, are we not? Comparing ourselves to other 951s, ferraris, vettes, 996tts, or whatever. A street car you use everyday, possble child seat (STs), get groceries, pick up chicks, or whatever. Reliable fun. The same fun and convenience you have with other cars; the same power is available at ALL times.
You could be taking a weekend getaway with your cool wife/girlfriend, but the rare chance to go headsup with the CarreraGT that just popped up in your rearview has eluded you because you're all out of race gas. This is real life; not the dyno world.
Again, I'm assuming we're comparing street cars. It's not really that user friendly of a street car if your whole life evolves around where your race gas supply is.
The S2 box will do nothing for his times.
10-19-2005, 02:12 AM
#114
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I understand what you are trying to get across and I do agree with some of it to a point.
Different people have will different opinions.
Maybe we can talk ST into doing a pump-gas run so we can see how he compares to everyone else.
Different people have will different opinions.
Maybe we can talk ST into doing a pump-gas run so we can see how he compares to everyone else.
10-19-2005, 08:02 AM
#117
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So right of now we got 3 sub 8 sec cars, that's seriously fast!
David with his 2.8, Corleone with his 2.5 and Tommy with a ??
Tommy please tell us about your engine!
Corleone did you run on E85 fuel?
I'm very exited to see vid's from ST's lightweight car. Preferably on pump gas but I won't complain about seeing a video with race fuel
David with his 2.8, Corleone with his 2.5 and Tommy with a ??
Tommy please tell us about your engine!
Corleone did you run on E85 fuel?
I'm very exited to see vid's from ST's lightweight car. Preferably on pump gas but I won't complain about seeing a video with race fuel
10-19-2005, 10:39 AM
#120
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I would say no to race gas as that is a "glory run" and not the purpose of the post. "real world"
Unless you run on a daily basis with race gas and super high boost.
Unless you run on a daily basis with race gas and super high boost.